The present invention relates to an airbag apparatus for lateral collision of an automobile.
As an airbag apparatus for an automobile, there is an airbag apparatus for lateral collision where an airbag is spread forward from a side portion of a backrest at a time of lateral collision of an automobile to protect a vehicle occupant (refer to Japanese Patent Application Laid-Open No. 9-136598 as a similar art).
This type of airbag has a generally L-shaped configuration, and is partitioned into an upper head protecting portion and a lower chest protecting portion by a partitioning wall cloth. An inflator is disposed in an opening, and gas discharged from a discharging hole provided at a side face of the inflator first enters into the chest protecting portion to spread the same forward and thereafter enters into the head protecting portion from a vent hole formed on the partitioning wall cloth to spread the same upward.
In such a conventional art, as the airbag is structured such that the chest protecting portion is first spread forward, a spreading speed of the chest protecting portion becomes much important. That is, in an airbag apparatus for lateral collision, a distance between a vehicle occupant and a vehicle body side wall is small, and it is necessary to spread the chest protecting portion between the vehicle occupant and the vehicle body side wall securely and instantaneously. It has been desired to propose a novel airbag apparatus capable of further increasing the spreading speed of the chest protecting portion.
The present invention has been achieved to meet such a requirement, and provides an airbag apparatus for lateral collision of an automobile capable of increasing a spreading speed of a chest protecting portion of an airbag.
The invention of a first aspect is an airbag apparatus for lateral collision of an automobile comprising a generally L-shaped airbag to be spread forward from a side portion of a backrest, the airbag being provided inside thereof with a partitioning wall cloth to partition the airbag into an upper head protecting portion and a lower chest protecting portion, and the partitioning wall cloth being formed with a vent hole to introducing gas into the head protecting portion, the gas to be discharged from an discharging hole of a side face of an inflator into the chest protecting portion, wherein a rear end of the partitioning wall cloth is positioned in a vicinity of a shoulder of a vehicle occupant and the partitioning wall cloth extends forward at a more downward angle than a perpendicular direction to the longitudinal direction of the inflator.
According to the invention of the first aspect, as the rear end of the partitioning wall cloth is positioned in the vicinity of the shoulder of the vehicle occupant, an upper end of the chest protecting portion (namely, the rear end of the partitioning wall cloth) becomes at least higher than the armpit position of the vehicle occupant, so that the airbag is prevented from entering into the armpit of the vehicle occupant. Accordingly, the chest protecting portion of the airbag is securely spread between the vehicle occupant and the vehicle body side wall. Also, as the partitioning wall cloth is extended forward at the more downward angle than the direction perpendicular to the direction of the longitudinal direction of the inflator while the height required for the chest protecting portion is secured in,this manner, the volume of the chest protecting portion becomes small, which results in improvement in forward spreading speed of the chest protecting portion correspondingly.
As a preferred aspect, the discharging hole for gas is formed at a lower end portion of the side face of the inflator.
According to this aspect, as the, discharging hole for gas is formed at the lower end portion of the side face of the inflator, and the gas is discharged from a bottom face of the chest protecting portion along an inner face thereof, the spread of the chest protecting portion is;accelerated so that the spreading speed thereof is further increased.
As another preferred aspect, in the airbag disposed in a front seat, the vent hole is provided at a rear side of the partitioning wall cloth.
According to this aspect, the vent hole formed at the rear side of the partitioning wall cloth is positioned just in the vicinity of the shoulder of the vehicle occupant. As the neck is positioned immediately above the shoulder in the vicinity thereof and there is a spatial surplus between the vicinity and the vehicle body side wall, as compared with the trunk of the body, the gas can securely be introduced into the head protecting portion through the vent hole formed in the extra space. Accordingly, the reliability and the speed in the spread for the head protecting portion are improved.
As a still another preferred aspect, in the airbag disposed in a rear seat, the vent hole is provided at a front side of the partitioning wall cloth.
According to this aspect, the gas is introduced from the vent hole provided at the front side of the partitioning wall cloth along a front side inner face of the head protecting portion. As the gas introduced along the front side inner face of the head protecting portion is made in a backward situation along the inner face of the head protecting portion as it is, the head protecting portion is spread slightly backward. Accordingly, the head protecting, portion contacts with a rear pillar formed in an oblique state in the vicinity of a rear seat at a situation where the head protecting portion further approaches to a right angle to the rear pillar, so that the airbag is facilitated to spread over a step of the rear pillar.
As a preferred aspect, a width-restricting cloth to connect the left and right faces of the airbag to restrict an expansion in the left and right directions of the airbag is provided in the chest protecting portion.
According to this aspect, as the volume of the chest protecting portion is made further small by the width-restricting cloth, the spreading speed of the chest protecting portion is further improved.
As a still further preferred aspect, a tuck portion is provided on a face of the airbag at a vehicle occupant compartment inner side and the tuck portion is formed by overlapping and sewing a portion of the airbag over a predetermined front and rear directional width.
According to this aspect, as the face of the airbag on the occupant compartment inner side is shorten by formation of the tuck portion, the airbag is spread with the airbag inclined towards the occupant compartment inner side. Accordingly, an interfering force of the airbag acting on the vehicle body side wall is weaken, thereby improving the reliability in the airbag spread. dr
FIG. 1 is a side view showing an airbag apparatus for lateral collision of an automobile according to a first embodiment of the present invention;
FIG. 2 is a perspective view showing an airbag;
FIG. 3 is a sectional view taken along arrow IIIxe2x80x94III in FIG. 2;
FIG. 4 is a side view showing an airbag apparatus for lateral collision of an automobile according to a second embodiment of the present invention and;
FIG. 5 is a sectional view taken along arrow Vxe2x80x94V in FIG. 4.